While tensile strain in the first Cu monolayer significantly destabilizes the adsorption strength, compressive strain in the first Au monolayer has a minimal impact on the heat of adsorption. Hence, this study introduces and, by comparison with previous experiments, validates an efficient DFT-based approach for strain-engineering the stability, and, in turn, the catalytic performance, of active sites in bimetallic alloys with atomic level resolution.The relationship between the excess volume and the structure of Fe-Cr-Ni melts is investigated using containerless levitation and in situ high-energy synchrotron x-ray diffraction techniques. https://www.selleckchem.com/products/LBH-589.html The density of six hypoeutectic Fe-Cr-Ni alloys along the 72 wt. % Fe isopleth was measured in the stable and undercooled regions, and the excess volume was evaluated as a function of Cr concentration. It is found that the 72Fe-Cr-Ni alloys exhibit a positive sign of excess volume and the amount increases with increasing Cr concentration. Analysis of the structure factor and pair distribution function of the alloy family reveals that the short-range order in the melt becomes more pronounced with decreasing Cr concentration; this demonstrates a direct correlation between the excess volume and local liquid structure. A characteristic signature of the icosahedral structure is observed in the structure factor of the melts, and the potential origin of the positive excess volume of the 72Fe-Cr-Ni alloys is qualitatively discussed in relation to the icosahedral structure.Yttria-stabilized zirconia (YSZ) is an important material with wide industrial applications particularly for its good conductivity in oxygen anion transportation. The conductivity is known to be sensitive to Y concentration 8 mol. % YSZ (8YSZ) achieves the best performance, which, however, degrades remarkably under ?1000 °C working conditions. Here, using the recently developed SSW-NN method, stochastic surface walking global optimization based on global neural network potential (G-NN), we establish the first ternary Y-Zr-O G-NN potential by fitting 28 803 first principles dataset screened from more than 107 global potential energy surface (PES) data and explore exhaustively the global PES of YSZ at different Y concentrations. Rich information on the thermodynamics and the anion diffusion kinetics of YSZ is, thus, gleaned, which helps resolve the long-standing puzzles on the stability and conductivity of the 8YSZ. We demonstrate that (i) 8YSZ is the cubic phase YSZ with the lowest possible Y concentrations. It is thermodynamically unstable, tending to segregate into the monoclinic phase of 6.7YSZ and the cubic phase of 20YSZ. (ii) The O anion diffusion in YSZ is mediated by O vacancy sites and moves along the ?100? direction. In 8YSZ and 10YSZ, despite different Y concentrations, their anion diffusion barriers are similar, ? 1 eV, but in 8YSZ, the O diffusion distance is much longer due to the lack of O vacancy aggregation along the ?112? direction. Our results illustrate the power of G-NN potential in solving challenging problems in material science, especially those requiring a deep knowledge on the complex PES.Understanding the defect chemistry of lead-halide perovskites and its effects on the hot-carrier lifetime is of significance for both fundamental understanding and applications as solar cell light absorbing materials. In this study, the mechanistic details of hot carrier decay in hybrid perovskites are investigated using a newly developed non-adiabatic molecular dynamics method. In this approach, the nuclear trajectory is based on Born-Oppenheimer ground state molecular dynamics, which is then followed by the evolution of carrier wave function including the detailed balance and decoherence effects. We found the longer decay time for hot electrons due to the incorporation of interstitial iodine in the hybrid lead-halide perovskites (MAPbI3), while the hot hole decay time is not affected significantly by the interstitial iodine. The underlying mechanism for such modulation of hot carrier dynamics is attributed to the changes of carrier density of states and the electron-phonon coupling strength. Hence, iodine interstitial is the necessary condition to create long-lived hot electrons in perovskites, which is further demonstrated by the comparative analysis with the pure MAPbI3.Optical properties of periodic arrays of nanoholes of a triangular shape with experimentally realizable parameters are examined in both linear and nonlinear regimes. By utilizing a fully vectorial three-dimensional approach based on the nonlinear hydrodynamic Drude model describing metal coupled to Maxwell's equations and Bloch equations for molecular emitters, we analyze linear transmission, reflection, and nonlinear power spectra. Rigorous numerical calculations demonstrating second and third harmonic generation by the triangular hole arrays are performed. It is shown that both the Coulomb interaction of conduction electrons and the convective term contribute on equal footing to the nonlinear response of metal. It is demonstrated that the energy conversion efficiency in the second harmonic process is the highest when the system is pumped at the localized surface plasmon resonance. When molecular emitters are placed on a surface of the hole array line shapes, the second harmonic signal exhibits three peaks corresponding to second harmonics of the localized surface plasmon mode and upper and lower polaritonic states.General exact analytical expressions have been derived for the image force energy Wi(Z, φ) of a point dipole in a classical three-layer system composed of dispersionless media with arbitrary constant dielectric permittivities εi. Here, i = 1-3 is the layer number, and Z and φ are the dipole coordinate and orientation angle, respectively. It was found that the long-range asymptotics Wi(Z→∞,φ) in both covers (i = 1, 3) are reached unexpectedly far from the interlayer (i = 2). Another specific feature of the solution consists in that the interference of the fields created by polarization charges emerging at both interfaces leads to the appearance of a constant contribution inside the interlayer with a non-standard dependence on the dipole orientation angle φ. It was shown that by changing the dielectric constants of the structure components, one can realize two peculiar regimes of the Wi(Z, φ) behavior in the covers; namely, there arises either a potential barrier preventing adsorption or a well far from the interface, both being of a totally electrostatic origin, i.